Method of installing helically preformed elements on cables



K. R. RUNDE Jan. 15, 1952 METHOD OF INSTALLING HELICALLY PREFORMED ELEMENTS 0N CABLES Filed July 8, 1946 FIG.5.

/NVEN7'OR KEN NETH R. RUNDE A r roe M Patented Jan. 15, 1952 METHOD OF INSTALLING HELICALLY PRE- FORMED ELEMENTS ON CABLES Kenneth R. Runde, Lemay, Mo., assignor, by mesne assignments, to Thomas F. Peterson,

Shaker Heights, Ohio Application July 8, 1946, Serial No. 681,903

1 Claim. (Cl. 57-161) This invention relates generally to means for protecting overhead electrical cables, and other types of electrical conductors, from damage resulting from vibration fatigue, abrasion, and other causes, and more specifically to such protective means which are known commercially as armor rods, and which comprise each a plurality of rods or elements which are preformed in helical form and which are arranged in embracing relation with respect to a portion of a conductor to provide a protective sheath thereabout at a desired point of the conductor, the predominant object of the invention being to provide such a protective means which is made up of preformed helical rods or elements that are preassembled into a self-sustaining sheath, tube, or sleeve which may be applied to a conductor sidewise thereof in a simple and expeditious manner.

Prior to this invention, armor rods of the type then known were applied to electrical conductors by a lineman, or other worker, who selected the proper number of loose and independent helically formed rods from a supply of such rods, and ar-. ranged said rods helically about a portion of the conductor to provide a continuous protective sheath, made up of said rods which embraced the conductod portion to be protected. This method of applying armor rods to a conductor waslacking in facility and was time-consuming because the worker was required to handle a number of long, loose rods which had to be maintained in their proper related positions while being applied to the conductor portion, and had to be guided and manipulated into their proper related positions about the conductor portion so as to produce a continuous protective sheath thereabout.

The outstanding feature of the present invention, and. the feature which difierentiates the protective device of this invention from the protective armor rod structures heretofore known, is that the protective structure of this invention is made up of preformed helical rods which are preassembled to provide an elongated, tubular protective structure which is completely self-sustaining, and may, as a matter of fact, be bent double without the individual rods being displaced from their proper positions in the structure. Because the preassembled protective structure of this invention is completely self-sustaining under all normal conditions it may be conveniently handled as a compact unit by a worker, and may be applied to a conductor portion in a simple and expeditious manner without the aid of complicated tools, as will be hereinafter explained.

Fig. 1 is a side elevation or the improved protective structure of the present invention.

Fig. 2 is an enlarged section taken on line 2-2 of Fig. 1. Fig. 3 is a View showing the improved protective structure in side elevation and illustrating the manner in which an ordinary screwdriver may be employed to aid in splitting the protec- 'tive structure into two portions which are unwrapped throughout a portion of the length of the protective structure preparatory to applying said protective structure to a conductor.

Fig. 4 is a view showing the partially unwrapped protective structure arranged adjacent to an electrical conductor preparatory to the operation of applying the protective structure to said conductor.

Fig. 5 is a view similar to Fig. 4 but showing the unwrapped portion of the protective structure, shown in Fig. 4, after it has been applied to an electrical conductor, and illustrating the manner in which the remainder of the protective structure is applied to the conductor with the aid of an ordinary screwdriver.

Fig. 6 is an enlarged fragmentary view of an end portion of the protective structure showing the manner in which the rods of the structure are flared to avoid the presence of sharp corners at the opposite ends of the protective structure.

Fig. 7 is a fragmentary view similar to Fig. 6 but illustrating a modified arrangement where certain sharp corners at the ends of the rods of the protective structure have been ground away.

Fig. 8 is a view illustrating the manner in which the protective structure may be applied to an energized electrical conductor with the aid of certain clamp-like tools.

Fig. 9 is a side elevation of one of the clamplike tools shown in Fig. 8.

In the drawings, wherein are shown for purposes of illustration, merely, two embodiments of the protective structure of the present invention, and two methods of applying said protective structure to electrical conductors, or like elongated elements, A designates the'protective structure generally. The protective structure comprises a plurality of elongated elements 1 which may be in the form of rods of round cross-section, or of other suitable shape, or said elements may be formed of materials other than metal which may be found to be suitable for the purpose' and may have any suitable cross-sectional shape. v

The plurality of elements 1 are preformed so as to be provided with permanent helical configurations, and said plurality of elements are preassembled to provide a hollow, tubular structure which is open at its opposite ends, said hollow tubular structure being made up of the proper number of elements I, and the helices of said elements having the proper pitch angles to provide a hollow tubular structure which is made continuous from end to end by the contacting relation of the helices of the various elements. The preassembled protective structure has been found to be completely self-sustaining and may be subjected to rather rough usage without any danger that the elements thereof may be displaced from their proper positions in the structure. As a matter of fact, when the elements I of the preassembled protective structure are formed of metal, or other inherently resilient material, a protective structure of the length employed in the use of this invention may be bent double without any of the elements I of the structure being displaced from their proper positions in the I protective structure.

Preassembly of the elements I can be accomplished in various ways to produce the hollow, tubular protective structure of this invention, one such being by wrapping the proper number of elements of proper cross-sectional size and having proper pitch angles, about a mandrel which is of slightly smaller cross-sectional size than an electrical conductor, or other elongated element, on which the protective structure is to be used. When a protective structure so preassembled is removed from the mandrel it is completely self-supporting and is ready for use, and because the opening extended longitudinally through the protective structure is of slightly less diameter than the diameter of a conductor, or other element, on which the protective structure is to be used, the protective structure will securely grip the outer surface of the conductor,

or other element, to which it is applied. Another way of preassembling the improved protective structure of the present invention is to manufacture preformed, hollow strand on a wire rope closing machine which would be equipped with preforming rollers, the hollow strand being cut into desired lengths after its formation on the wire rope closing machine.

In order to avoid sharp edges at ends of the elements I which are present at opposite ends of the opening extended longitudinally through the protective structure A, the end portions of said elements I are flared slightly as is shown to good advantage at 2 in Fig- 6. Thus, sharp edges are eliminated at the opposite ends of the longitudinal opening of the protective structure. which, if present, might nick a conductor, or other element, to which the protective structure would be applied. As an alternate way of eliminating the sharp edges referred to, a cone-shaped emery wheel (not shown) may be introduced into the opposite ends of the longitudinal opening of the protective structure A and operated therein to grind away such sharp edges, as is shown by dotted lines at 3 in Fig. 7.

In applying the improved protective structure of the present invention to a de-energized electrical conductor, an ordinary screwdriver, or other suitable tool is inserted between elements of the protective structure adjacent to an end thereof, as is suggested in Fig. 3, wherein a screwdriver is designated by the reference character 4. The protective structure is thus divided by the screwdriver 4 into two groups of elements I, and these two groups of elements are unwrapped, as

is shown in Fig. 4, for distance equal to approximately one-half of the length of the protective structure. The partially unwrapped protective structure is then arranged with respect to an electrical conductor, or other elongated element 3, as is shown in Fig. 4, and the unwrapped portion of the protective structure A is re-wrapped so that it embraces a portion of the conductor B, the re-wrapped, conductorembracing portion of the protective structure being shown in Fig. 5 wherein it is designated by the reference character A. The screwdriver 4 is then inserted, at the approximate position illustrated in Fig. 5, between a part of the unapplied portion A of the protective structure and the conductor B, and by rotating the screwdriver in the direction of the lay of the elements I, as suggested by the arrow in Fig. 5, the portion A" of the protective structure will be rotated about the conductor. This forces the hollow protective structure over the conductor as the screwdriver is rotated thereby completing the application of the protective structure to said conductor.

When the improved protective structure is to be applied to an energized conductor a pair of tools such as those illustrated in Fig. 8 are employed. The particular tools shown in Fig. 8 are designated by the reference characters Ca and Cb and are in the form of clamps, each of said tools comprising a body portion 5 (see Fig. 9) which is shaped to provide a fixed jaw 6, a body portion extension I which is provided with a screwthreaded socket 8, a screwthreaded adjusting element 9 which is screwthreadedly supported by said socket for adjustment with respect thereto, a movable jaw I0 supported by the upper portion of said adjusting element, and an eye portion II at the lower portion of said adjusting element. The body portion of each of the tools Ca and Cb is provided with an upwardly projected portion I2 which is provided with an aperture I3 formed through the upper portion thereof, and also the body portion of each of said tools has opposed apertures I4 formed therethrough which are located at opposite sides of the fixed jaw 6 of the tool.

In applying the protective structure to an energized electrical conductor, such as that designated by the reference character B in Fig. 8, the protective structure is first split into two groups of elements I with the aid of a screwdriver, or other suitable tool, and the two parts of the split portion of the protective structure are unwrapped for a distance of approximately one-half of the length of the protective structure, as has been previously explained herein. The two groups of the elements I of the unwrapped portion of the protective structure are then threaded through the openings I4 of the tools Ca and Cb, one group of the elements I being threaded through apertures I4 located at corresponding sides of the tools, and the other of said groups of elements being threaded through the apertures at the opposite corresponding sides of the tools.

The protective structure and the tools Ca and Cb are then elevated with the aid of insulating tools to the position of the energized conductor B so that the protective structure assumes the approximate position with respect to said conductor in which it is shown in Fig. 8, the tool Cb being located at the junction of the wrapped and unwrapped portions of the protective structure,

while the tool Ca is spaced apart slightly from the tool Cb in the direction of the length of the unwrapped portion of the protective structure.

The adjusting element 9 of the tool Cb is screwed upwardly with the aid of an insulating clamp stick, or other suitable tool so as to cause the movable jaw of said tool Cb to forcibly engage the underside of the conductor B and thus cause the tool Cb to be held stationary. The tool Ca, whose movable jaw I0 is positioned so that it does not closely engage the underside of the conductor B, is thenrotated, with the aid of a suitable insulating tool, about said conductor B in the direction of the lay of the elements 1 of the protective structure, and is moved slowly longitudinally of the conductor B toward the outer end of the unwrapped portion of the protective structure, the rotation about the conductor B of the aperture l4 through which the two groups of elements pass, causing said two groups of elements to be laid on the conductor in their proper helical arrangement.

When the portion of the protective structure which had been unwrapped has been arranged about the conductor as described above, and the tool Ca has passed outwardly of the end of the protective structure toward which it was moved, said tool Cu i removed from the conductor by backing up its movable jaw l0 and moving the tool laterally of the conductor. The tool Cb is then rotated, with the aid o1 a suitable insulating tool, about the conductor B in the direction of the lay of the elements I of the protective structure and is moved toward the ri ht-hand end of said protective structure, as same is illustrated in Fig. 8, the movable jaw ID of said tool Cb having first been backed up to permit such movement of said tool. This will cause the two groups of the elements I of the protective structure to be unwrapped from the hollow strand which comprises the protective structure and re-wrapped helically about the conductor to complete the application of the protective structure to the conductor, where- The method of applying to an elongated memher a protective structure which comprises a plurality of helically shaped elements that are preassembled to provide a self-sustaining elongated hollow structure, said method comprising dividing said elements of said hollow structure into two groups of elements and unwrapping said groups of elements for a portion of the length of the hollow structure, wrapping said unwrapped portions of the hollow structure helically about said elongated member by a tool while holding the remainder thereof with a second tool, and then applying the remainder of the hollow structure to said elongated member with the aid of said second tool which is rotated about said elongated member to correspondingly rotate said remainder of the hollow structure so that the element portions making up said remainder of the hollow structure are extended helically of said elongated member.

KENNETH R. RUNDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 630,635 Sundh Aug. 8, 1899 840,766 Greenfield Jan. 8, 1907 2,095,599 Gleason et al Oct. 3, 1937 2,414,136 Bodendieck Jan. 14, 1947 FOREIGN PATENTS Number Country Date 194,993 Germany Nov. 7, 1905 

